Metal has been used to enhance the burning rate of solid propellant compositions. The metal has been added to uncured solid propellant compositions in various forms, e.g., ribbons, powder, staples, spheroidal, and other geometric shapes.
More recently, U.S. Pat. No. 4,092,189 issued to Robert E. Betts on May 30, 1978 and assigned to the United States of America as represented by the Secretary of the Army, Washington, D.C., is directed to a method of preparing high burning rate solid propellant grains that have good mechanical properties. This patent covers a high burning rate solid propellant grain prepared from a multimodal blend of at least one ultra-high burning rate propellant that has been cured and ground to a predetermined particle size of from about 100 microns (0.1 millimeter) to about 5 millimeters and at least one uncured propellant composition that has high tensile strength and compatibility with the ultra-high burning rate propellant and that serves as a binder for the solid propellant grain when cured.
The method of U.S. Pat. No. 4,092,189 includes preparing a cured ultra-high burning rate propellant that is subsequently ground and screened to a predetermined particle size. The ground and screened propellant is then combined with uncured propellant that is subsequently cured to yield a high burning rate solid propellant grain with good mechanical properties.
An improvement to the burning rate technology provided by an improved process in producing the enhancer for propellant burning rate and the technique of using the enhancer for propellant burning rate would be welcomed additions to the propulsion industry art.
Therefore, it is an object of this invention to provide a means for effecting a major increase in the burning rate of solid propellants.
Another object of this invention is to provide burning rate enhancement of solid propellants by means of metal/oxidant agglomerates.
A further object of this invention is to provide metal/oxidant agglomerates which are prepared by an improved method wherein the agglomerates formulation is slurred in a fluorinated and/or chlorinated hydrocarbon solvent at ambient temperature to form agglomerates in mixture, followed by maintaining the mixture at 135 degrees Fahrenheit with stirring, and with continued stirring while the mixture is maintained under reduced pressure to remove any residual solvent. Subsequent curing of the agglomerates is accomplished at 150-170 degrees Fahrenheit for about 24 hours.